Vibration characteristics of MR cantilever sandwich beams: experimental study

Abstract

The concept of vibration controllability with smart fluids within flexible structures has been in the
\ncentre of interest in the past two decades. Although much research has been done on structures with
\nembedded electrorheological (ER) fluids, there has been little investigation of magnetorheological (MR)
\nfluid adaptive structures. In particular, a body of research on experimental work of cantilever MR
\nbeams is still lacking. This experimental study investigates controllability of vibration characteristics of
\nmagnetorheological cantilever sandwich beams. These adaptive structures are produced by embedding
\nan MR fluid core between two elastic layers. The structural behaviour of the MR beams can be varied
\nby applying an external magnetic field to activate the MR fluid. The stiffness and damping structural
\ncharacteristics are controlled, demonstrating vibration suppression capabilities of MR fluids as
\nstructural elements. MR beams were fabricated with two different materials for comparison purposes.
\nDiverse excitation methods were considered as well as a range of magnetic field intensities and
\nconfigurations. Moreover, the cantilever MR beams were tested in horizontal and vertical
\nconfigurations. The effects of partial and full activation of the MR beams were outlined based on the
\nresults obtained. Controllability of the beam’s vibration response was observed in the form of
\nvariations in vibration amplitudes and shifts in magnitudes of the resonant natural frequency.